Version 2.0.0 test failure on macos-homebrew

[sim642]

ocaml/opam-repository#24493 reveals test failures on macos-homebrew:
goblint-cil.2.0.0.macos-homebrew.txt
Namely:

- ------------ [418] CC="gcc-13" make testrungcc/builtin_object_size OPTIMIZE=1 ------------
- 
- [418] A regression test command failed:
-   CC="gcc-13" make testrungcc/builtin_object_size OPTIMIZE=1
-

[sim642]

GobCon decision: use #ifdef to disable the test on OSX/arm64.

[sim642]

This has somehow gotten a lot worse. Now in our CI all non-M1 MacOS tests seem to be failing: https://github.com/goblint/cil/actions/runs/10073492596.

[sim642]

There are 50 occurrences of this in one of the logs:

/Library/Developer/CommandLineTools/SDKs/MacOSX13.sdk/usr/include/sys/stdio.h[47:80-86] : syntax error

Is this the same as #168 but also on OSX 13, not 15?

[sim642]

Extracting the file from CI, it is

int     renameat(int, const char *, int, const char *) __OSX_AVAILABLE_STARTING(__MAC_10_10, __IPHONE_8_0);

which indeed preprocesses to the same availability crap.